• Proceedings of the Microbiological Society of Korea Conference
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• 2008.05a
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• pp.37-37
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• 2008

• Journal of dental hygiene science
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• v.23 no.4
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• pp.343-350
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• 2023

Background: Digital panoramic dental X-ray equipment (PDX) is frequently used by patients and dental workers for diagnosis and examination in dental institutions; however, infection control has not been properly implemented. Therefore, in this study, we aimed to systematically review the potential risk of cross-infection in the dental environment by investigating the contamination level of general aerobic bacteria and Staphylococcus aureus, which are important in hospital infections, in PDX areas that people mainly contact. Methods: This survey was conducted from March to May 2023 and covered one general hospital, three dental hospitals, and nine dental clinics equipped with PDX. Bacteria samples were collected from the left-handle, right-handle, forehead support, and head side support as the patient's contact areas, as well as the X-ray exposure switch and left-click mouse button as the dental hygienist's contact areas of the PDX. The collected bacteria were spread on Petrifilm, and colonies formed after 48 hours of culture were counted. Results: General aerobic bacteria and S. aureus were detected in all areas investigated. Significant differences in bacterial counts between different regions of the PDX were observed in both groups (p<0.001). The detection rates of general aerobic bacteria (p<0.001) and S. aureus (p<0.001) were significantly higher in the contact areas of patients than those of dental hygienists. A positive correlation was observed between the forehead and the temple region in terms of general aerobic bacteria and S. aureus detection (r=1) (p<0.01). Conclusion: Taken together, the presence of many bacteria, including S. aureus, detected in PDX indicates that PDX has a potential cross-infection risk. Our results therefore highlight the need for the development of appropriate disinfection protocols for reusable medical devices such as PDX and periodic infection prevention training for hospital-related workers, including dental hygienists.

• Journal of radiological science and technology
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• v.24 no.1
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• pp.27-32
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• 2001

The bacteria infection on film cassette contact surface was examined at the diagnostic radiology department of the S. hospital. The objective of this study was to assess the contamination level on film cassette contact surface as a predictor of patient prevention from nosocomial infection and for improvement of the hospital environment. The laboratory result was identified non-pathologic bacterial in the five different cassette size of the contact surface. Film cassettes were exposed to ultraviolet light for 1, 2 and 3 minutes. Ultraviolet light disinfection is proven suitable for bacteria. The study concludes that presence of a bacterial infection will prevent a using antiseptic technique on film cassette contact surface. In addition education of nosocomial infection for radiographers will be required. In conclusion, ultraviolet is considered effective to irradate bacteria. Additionally, two minutes are required to sterilize film cassettes.

• International Journal of Oral Biology
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• v.30 no.2
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• pp.65-69
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• 2005

Periodontitis is a multi-microbial disease and the comparison of a series of periodontopathogenic and non-periodontopathogenic bacteria in terms of microbe-host interaction may provide clues to understand the microbial etiology of the disease better. When we deal with twenty different bacterial species in a study, the first technical issue is how to measure the accurate concentration and use the same number of bacterial cells. We measured bacterial concentration by enumerating bacteria stained with SYTOX green for constant time using a flow cytometer and compared the results with those obtained by plate counting. Concentrations calculated by two different methods were very close. Therefore, flow cytometric counting allowed the rapid analysis of live/dead bacteria, offering the advantage of turbidity measurement and that of colony counting together.

• Biomedical Science Letters
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• v.29 no.4
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• pp.256-262
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• 2023

The purpose of this study is to investigate microbial contamination in water purifiers from two universities (A and B) in Chungcheong region and to evaluate about the harmfulness of the isolated bacteria to the human. The degree of microbiological contamination of six water purifiers at university A was investigated three times from July 2018 to September 2019, and nine water purifiers at university B were investigated in 2023. The isolated bacteria were biochemically identified using an API kit and Vitek-2 system, and then the bacteria were identified to the species level using MALDI-TOF MS. In addition, the possibility of human infection of the isolated bacteria was evaluated through a literature search. In July 2018 and September 2019, the number of bacteria isolated inside the faucet was below the acceptable standard for hot water, but exceed for cold water in all water purifiers. In January and September 2019, bacteria exceeding the acceptable standards were isolated nine times from the cold water of six water purifies (a total of 12 water purifiers). Bacteria identified by MALDI-TOF MS included anaerobic bacteria (Clostridium novyi, Clostridium themopalmarium etc.), Gram-positive bacilli (Microbacterium testaceum, Arthrobacter woluwensis etc.), and Gramnegative bacilli (Acinetobacter nosocomialis, Comamonas kerstersii etc.), which are difficult identify by biochemical methods. In conclusion, bacteria exceeding the acceptable standard were isolated from the cold water of most of the water purifiers. Most of the isolated bacteria were low-pathogenic bacteria from natural environment, but opportunistic bacteria that can cause infection in humans were also isolated from some water purifiers.

• Journal of Korean Academy of Nursing
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• v.19 no.3
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• pp.249-258
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• 1989

The purpose of study was to confirm theory about the effectiveness of routine mental care on the reduction of catheter-associated urinary tract infection. The study was carried out at a university hospital from September 1,1987 to April 17, 1989 : 32 Patients with a foley -catheter were studied. The study compared the urinary tract infection rate of an experimental group with that of a control group and tested the antibiotic susceptibility of the isolated bacteria. The experimental group(16 patients) was given daily meatal care with 10% Betadine for periods ranging from 4 to 21 days. The control group(16 patients) was not given that care. The results obtained were as follows : 1. The urinary tract infection rate of the experimental group was 50.0 %, and that of the control group 43.8%. There was no significant difference between the groups. 2. Organisms isolated in the control group were bacteria 100%, and in the experimental group bacteria 50% and fungus 50%. The most common organisms of the 15 strains isolated in the total group were Staphylococcus coagulase negative (3 patients), and E-coli (3 patients). 3. Most of bacteria isolated in this study were sensitive to Norfloxacillin, but resistant to Ampicillin, Chloramphenicol, Kanamycin, Tetracycline, and Erythromycin. Hence the importance of controling catheter-associated urinary tract infections. Findings suggest the need to search for other sources of infection, further experimentation controling various sources of urinary tract infection and larger group of subjects.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.49 no.4
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• pp.316-324
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• 2004

Sinorhizobium sp. strain MUS10 forms nitrogen-fixing stem nodules on Sesbania rostrata, a tropical green manure crop. In this study, the ultrastructural events associated with the formation of stem nodules were investigated. Sinorhizobium sp. strain MUS10 entered the host tissue through cracks created by the emerging adventitious root primordia and multiplied within the intercellular spaces. During early phases of infection, host cells adjacent to invading bacteria revealed cellular damage that is typical of hypersensitive reactions, while the cells at the inner cortex exhibited meristematic activity. Infection threads were numerous in S-day-old nodules and often were associated with the host cell wall. In several cases, more than one infection thread was found in individual cells. The junction at which the host cell walls converged was often enlarged due to fusion of intracellular branches of infection threads resulting in large infection pockets. The infection threads were made up of a homogeneous, amorphous matrix that enclosed the bacteria. Several finger-like projections were seen radiating from these enlarged infection threads and were delineated from the host cytoplasm by the plasma membrane. As in Azorhizobium caulinodans induced root nodules, the release of Sinorhizobia from the infection threads into the plant cells appears to be mediated by 'infection droplets'. A 15-day­old Sesbania stem nodule revealed typical ultrastructure features of a determinate nodule, containing several bacterioids within symbiosomes.

• The Korean Journal of Emergency Medical Services
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• v.20 no.3
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• pp.49-56
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• 2016

Purpose: The purpose of this study was to investigate the effect of a pathogenic bacteria filtration instrument for infection prevention during mouth-to-mouth ventilation. Methods: Two kinds of face shields were used for the study. One rescuer blew the filter through a bag valve mask and the filter was then cultured for bacteria. The mask was tested both on the front and back side. Results: Two kinds of face shields including the KF shield and CM shield were tested. The KF shield has received national certification and it prevented transmission of bacterial infection but the CM shield showed the opposite result and did not prevent bacterial transmission. Pathogenic bacteria were found on the back of the CM shield. Conclusion: A certified face shield is very important to prevent bacterial transmission. Face shields should be demonstrated and used by paramedic students.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.31 no.4
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• pp.322-328
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• 2005

Oral and maxillofacial infections are most commonly odontogenic in origin. The present study was implemented for patients with oral and maxillofacial infections in order to determine what differences were present in cultured bacteria, depending upon the different types of infection. For the present study, the epidemiological characteristics, the state of infection, and the results of the pus culture and antibiotic susceptibility tests were analyzed for the 159 cases where pus culture tests were performed. The patients were treated at the Oral and Maxillofacial Surgical Department of Chonnam National University Hospital during an 18-months period from March 2003 to August 2004. Among the total 159 pus culture specimens, bacteria were cultured in 111 cases (69.8%). In the 111 pus culture specimens, Streptococcus species, Neisseria species, and Staphylococcus species were cultured from 69 cases (51.1%), 21 cases (15.6%), and 15 cases (11.1%), respectively and were determined to be bacterial strains the predominant bacteria responsible for oral and maxillofacial infectious diseases. Twenty four cases (15.1%) among the 159 specimens showed mixed infections. The mostly isolated bacteria from each of the space abscess, dentoalveolar abscess, inflammatory cyst, and pericoronitis cases were the Viridans streptococci. There was little relevance between the type of infection and the type of cultured bacteria. Antibiotic susceptibility tests showed a high level of susceptibility to teicoplanin(100%), vancomycin(100%), chloramphenicol(96.4%), ofloxacin(88.3%), imipenem(83.3%), erythromycin(82.5%) and a low susceptibility to cefazolin(40.0%), oxacillin(44.7%), ampicillin(49.4%), penicillin(51.1%). These results indicate that there was no significant difference among the cultured bacteria depending on the type of infections and their susceptibility to cephalosporin and penicillin G was low.

• Korean Journal of Digital Imaging in Medicine
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• v.13 no.3
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• pp.105-109
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• 2011

With the development of medical technologies and the growth of household incomes, most of the people have become to be interested in health as it leads to significant early detection and cure of diseases. However the pattern of disease becomes diverse and it makes the imaging diagnosis department crowded with many patients. Therefore the opportunistic infection could be serious there. The hospital becomes the place which provides high risks of infection danger but it is true that the opportunistic infection of the hospital employees is not still recognized well. The imaging diagnosis department has developed a lot but it becomes the medium of secondary infection of patients and employees. So this study analyzesthe status of bacteria infection of the examination table, the handle of diagnostic equipment and the hands of radiation staffs in imaging diagnosis department of the general hospitals and individual ones. And the result shows that some bacteria were found even though it's little. We are trying to make the hospitals to be free of secondary infection securing safety measure to prevent the secondaryinfection from occurring to patients and hospital employees.